The D flat minor eleventh chord is a 6-note chord consisting of the notes Db, Fb, Ab, Cb, Eb and Gb.
You can see these notes highlighted in the interactive piano chart below.
The chord itself is often abbreviated as Dbm11.
Interactive piano diagram for the D flat minor eleventh chord
Chords that are a subset of Dbm11. These contain less notes but all of them are included in Dbm11.